[PATCH v3 4/6] drm/meson: vclk: add DSI clock config

[Neil Armstrong]

The DSI path used the ENCL pixel encoder, thus this adds a clock
config using the HDMI PLL in order to feed the ENCL encoder via the
VCLK2 path and the CTS_ENCL clock output.

Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
---
 drivers/gpu/drm/meson/meson_vclk.c | 47 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/meson/meson_vclk.h |  1 +
 2 files changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/meson/meson_vclk.c b/drivers/gpu/drm/meson/meson_vclk.c
index 2a82119eb58e..5e4d982be1c8 100644
--- a/drivers/gpu/drm/meson/meson_vclk.c
+++ b/drivers/gpu/drm/meson/meson_vclk.c
@@ -55,6 +55,8 @@
 #define VCLK2_DIV_MASK		0xff
 #define VCLK2_DIV_EN		BIT(16)
 #define VCLK2_DIV_RESET		BIT(17)
+#define CTS_ENCL_SEL_MASK	(0xf << 12)
+#define CTS_ENCL_SEL_SHIFT	12
 #define CTS_VDAC_SEL_MASK	(0xf << 28)
 #define CTS_VDAC_SEL_SHIFT	28
 #define HHI_VIID_CLK_CNTL	0x12c /* 0x4b offset in data sheet */
@@ -83,6 +85,7 @@
 #define VCLK_DIV12_EN		BIT(4)
 #define HHI_VID_CLK_CNTL2	0x194 /* 0x65 offset in data sheet */
 #define CTS_ENCI_EN		BIT(0)
+#define CTS_ENCL_EN		BIT(3)
 #define CTS_ENCP_EN		BIT(2)
 #define CTS_VDAC_EN		BIT(4)
 #define HDMI_TX_PIXEL_EN	BIT(5)
@@ -1024,6 +1027,47 @@ static void meson_vclk_set(struct meson_drm *priv, unsigned int pll_base_freq,
 	regmap_update_bits(priv->hhi, HHI_VID_CLK_CNTL, VCLK_EN, VCLK_EN);
 }
 
+static void meson_dsi_clock_config(struct meson_drm *priv, unsigned int freq)
+{
+	meson_hdmi_pll_generic_set(priv, freq * 10);
+
+	/* Setup vid_pll divider value /5 */
+	meson_vid_pll_set(priv, VID_PLL_DIV_5);
+
+	/* Disable VCLK2 */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_EN, 0);
+
+	/* Setup the VCLK2 divider value /2 */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV, VCLK2_DIV_MASK, 2 - 1);
+
+	/* select vid_pll for vclk2 */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
+			   VCLK2_SEL_MASK, (0 << VCLK2_SEL_SHIFT));
+
+	/* enable vclk2 gate */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_EN, VCLK2_EN);
+
+	/* select vclk2_div1 for encl */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
+			   CTS_ENCL_SEL_MASK, (8 << CTS_ENCL_SEL_SHIFT));
+
+	/* release vclk2_div_reset and enable vclk2_div */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV, VCLK2_DIV_EN | VCLK2_DIV_RESET,
+			   VCLK2_DIV_EN);
+
+	/* enable vclk2_div1 gate */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_DIV1_EN, VCLK2_DIV1_EN);
+
+	/* reset vclk2 */
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_SOFT_RESET, VCLK2_SOFT_RESET);
+	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_SOFT_RESET, 0);
+
+	/* enable encl_clk */
+	regmap_update_bits(priv->hhi, HHI_VID_CLK_CNTL2, CTS_ENCL_EN, CTS_ENCL_EN);
+
+	usleep_range(10000, 11000);
+}
+
 void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 		      unsigned int phy_freq, unsigned int vclk_freq,
 		      unsigned int venc_freq, unsigned int dac_freq,
@@ -1050,6 +1094,9 @@ void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 		meson_vclk_set(priv, phy_freq, 0, 0, 0,
 			       VID_PLL_DIV_5, 2, 1, 1, false, false);
 		return;
+	} else if (target == MESON_VCLK_TARGET_DSI) {
+		meson_dsi_clock_config(priv, phy_freq);
+		return;
 	}
 
 	hdmi_tx_div = vclk_freq / dac_freq;
diff --git a/drivers/gpu/drm/meson/meson_vclk.h b/drivers/gpu/drm/meson/meson_vclk.h
index 60617aaf18dd..1152b3af8d2e 100644
--- a/drivers/gpu/drm/meson/meson_vclk.h
+++ b/drivers/gpu/drm/meson/meson_vclk.h
@@ -17,6 +17,7 @@ enum {
 	MESON_VCLK_TARGET_CVBS = 0,
 	MESON_VCLK_TARGET_HDMI = 1,
 	MESON_VCLK_TARGET_DMT = 2,
+	MESON_VCLK_TARGET_DSI = 3,
 };
 
 /* 27MHz is the CVBS Pixel Clock */
-- 
2.25.1